Marine antenna unit



FIG. 1 is a perspective view of a marine antenna unit showing my new design;

FIG. 2 is a side view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines in FIG. 1, showing attached structure, are for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a marine antenna unit, as shown and described. 